I rebut two previous posts:
T3 mining--having blown up an assload of Sleepers I can say that they show no signs of industrial activity. The lack of verisimilitude would be astounding. I also fail to see how the versatility provided by sub-systems would be put to good use by mining ships. I'd rather see T3 confined to combat ships. T3 frigs, yes! T3 mining barge, puh-lease!!!
Caldari inty boosts--all Caldari can hang. If you don't like how slow they are, add a med extender to the mids. See how many hp you have?

CCP seems really attached to those specialties.

Mining output: first and most visible balancing factor, plan is to increase all barge mining output to be within an acceptable margin of the Hulk, not miles behind as it is currently.

they also removed drone alloys and t1-modules from loot. so there are fewer minerals to begin with and overall more gear to be produced. even if noone would by t1 and for t2, t1 is still needed to build t2.
i guess, there will be need for some more minerals. maybe the prices will go down a bit but they are quite high atm.

secondly, as MortisLegati mentioned already, they plan to buff only the mining ships which are worse than the hulk atm.
so while there will be some more minerals coming from the buffed "noobs" the max yield per character does not change.
regarding the big picture, there will not be a big change.

your last two post convey two different things, at least as i understand them.

in the first, the one i quoted, you raised concerns about a collapsing market due to more resources available because "lower" tier mining vessels yielding more ore.
in the second post you displayed the differences in income generated by missions and mining.

i do not get the point you want to make :(
do you suggest, more minerals would bring the mineral prices down to a normal level and thereby further decrease the income a miner generates?
then, i fail to see how that would collapse the market. yes, it would make mining even less desireable than it already is, but a market collapse

... dunno. the prolonged hulkageddon seems to be more disruptive, imo. it opens up possibilities for everybody not mining in high sec, but it definitely decreases the economical output of high sec.

or was there another point you wanted to make?

all in all, we have to wait for the changes to be expressed in hard numbers, before any decent conclusion can be drawn, i guess ^^

I like the idea of rebalancing the mining ships, and while I have not read all 40 some pages of replies so I am not sure if this has been suggested or not, I belive that there should be a ship class capable of transporting between 50,000 and 75,000 m3 base with decent amout of speed for a ship that size say 90mps and warp around 3 AU/s. Give it some decent sheild and armor and a couple of slots to customize it. Maybe even a turret or lancher slot depending on race. Maybe I'm alone in this thinking, but we have something like a pickup truck size craft, or a tractor trailer size ship with no delivery truck catigory. It just seems like a long way to me between 6,000m3 even maxed out with rigs and expanders around 42k m3 and the standard freighter of over 720,000 m3 cargo hold. Seems like there should be ships capable of transporting an out post but not an entire station.

But still if you add a fuel bay and give it the ability to compress ore as you mine an Orca would be a nice mining platform.Something for higher skilled players to look forward to and not just reworked barges.

CCP will never release T3 ORE ships, becuase of hulkageddon and all the suicide attacks on miners. Even in the dev blog, they said they are only designing new mining ships to deal with hulkageddon and suiciders. T3s would cost too much when lost, and be a high gank target.

If anything, this expansion is only nice, since it might be cheaper to die while mining.

i think the new part of the cargo hold is for ore only and it will have a separate (normal) cargo hold as well